Plugging device for door locks



July 3, 1951 I P. SEVCIK PLUGGING DEVICE FOR DOOR LOCKS Filed Dec.

IN VEN TOR.

Patented July 3, 1951 UNITED STATES PATENT OFFICE PLUGGING DEVICE FORDOOR LOCKS Paul sevinohica o, Ill.

Application December 18, 1947, Serial No. 792,536

8 Claims. 1

My invention relates to door locks of the mortise type, and moreparticularly to those found in hotels, rooming houses and the like. Suchlocks usually receive a skeleton key, and therefore offer littlesecurity against unauthorized entrance to the premises. It is thereforeone object of the present invention to provide a device which anoccupant can use for plugging the keyholes of the lock when retiring orleaving the premises, so that it will be impossible for anyone to inserta key into the look from the outside.

A further object is to provide a unit which is insertible into the lookfrom the outside or the inside by way of the keyhole and has a controlfor expanding the unit inside the lock to constitute a plug for thesame.

Another object is to provide a control which is easily removable fromthe plugging device by the user thereof, whereby to leave no projectionor sign in front of the door which may invite curiosity or tampering.

An important object is to provide the device with few and simple partsand in a manner to admit of fine variations and combinations in itscontrol, in order to prevent the easy duplication thereof.

With the above objects in view, and any others which may suggestthemselves from the descrip tion to follow, a better understanding ofthe invention may be had by reference to the accompanying drawing, inwhich Fig. 1 is a side elevation of the look as mounted in a fragment ofa door;

Fig. 2 is a section on the line 2-2 of Fig. 1, showing the plugging unitand its control separated therefrom;

Fig. 3 is an enlarged elevation of the device, showing the controlfitted in the plugging unit, and the latter in the normal or contractedpositions;

Fig. 4 is a bottom plan view of the showing in Fig. 3, with the controlpartly broken away;

Fig. 5 is an enlarged section on the line 5-5 of Fig. 3, partly inelevation and in the plugging of a housing It and a control key It.Ordinarily the plugging unit is carried by the key 16, and Fig. 2 showsthat such unit has been inserted to pass through the lock iii by way ofthe keyholes ii, and that the key it has been withdrawn from theplugging unit. The rear portion of the housing [5 is wrapped with ajacket ll which gathers underneath with doubled wings 18, these leadinginto the first keyhole H and retaining the housing i5 against turningmotion. However, the key it is intended to be given turning motion andtherefore receive a swivel eye at for attachment to a chain, tag orother holder.

The principle of the plugging device is to introduce a pair of foldedhinge plates into the lock it by way of the receiving keyhole, and thento. have such plates spread and form a bar against the retraction oradvance of the plugging unit. With the latter lodged in the look noordinary key can be inserted into the same from either side of the door.

To operate as described, the plugging device is constructedsubstantially as shown in Figs. 5 to 7. In these figures it is indicatedthat the housing l5 contains a tubular slide 22 which is thickened atits rear end as indicated at 23 and tapped as shown at 24 to receive ascrew 25 extended from a stem 26 forming a reduction of the key IS. Theslide 22 has registering diametrical slots 2'! through which a cross-pin29 carried by the housing i5 passes. Thus, when the key It is insertedinto the rear end of the housing as indicated in Fig. 5, with the screw25 directed toward the tapped bore 26, the stem 26 makes a sliding fitin such end and starts the screw 25 in the bore 24 as the shoulderformed by the stern on the key it meets the housing. With the key inthreading rotation, the thickened portion 23 acts as a traveling nut tomove the slide rearwardly. It follows, therefore, when the turning ofthe key it is reversed, that the movement of the slide is forward untilit rides oil the screw 25, in which event the key It can be retractedand removed.

The hinge plates previously referred to are indicated at 30 in Figs. 5and 7; and Fig. 6 shows their alternate hinge ears 3| journaled on acenter rod 3Ia carried by a plug 32 which forms a frontal closure forthe housing. A slide bar 33 is located beneath the housing l5 andoperates in a slot 33a in the Wings 3. The slide bar is connected formotion with the slide 22 by a stud 34 which is fitted into a thickenedmedial portion 35 of the slide. Clearance for the stud is made by abottom slot 36 made in the housing l5. The slide bar 33 has its forwardend in the form of a wedge 31. An outward extension 38 of the stud 34serves as an anchor for a hairpin spring 39 whose arms spread againstthe inner faces 01 the hinge plates 30, threading through openings 4B inthe same. The hairpin spring is thus retained in engagement with thehinge plates, and its function is to lead with a spreading influence onthe hinge plates before the wedge enters between them.

A compression spring 45 between the hinge ears 3| and the front end ofthe slide 22 serves to urge the latter to the forward position shown inFigs. 5 and 6. This action also advances the wedge 37 between the hingeplates 38 to spread them as indicated in Figs. 5 and 7. However, therearward motion of the slide acts to gather the hinge plates through theagency of Oblique cams it formed by a longitudinal V-cut made in thebottom wall of the slide; and the backing of the slide withdraws thewedge 31 atthe same time to allow the hinge plates to gather.

It has been mentioned that the plugging unit is ordinarily carried bythe key it. Since the latter is necessarily joined to the unit by thescrew 25 threaded into the slide, it follows that the hinge plates 38are in gathered relation, making the plugging device compact enough tobe carried in the pocket or from a key ring or chain. Now, in case it isdesired to plug the door look from the outside when leaving or from theinside when retiring it is only necessary to insert the plugging unitinto the look from the corresponding side of the door and rotate the key[6 in the unthreading direction. As this is done, the spring 45 bearsforwardly on the slide, urging it to ride off the screw 25. At the sametime the slide cams 46 become more widely spaced, permitting the arms ofthe hairpin spring 39 to urge the hinge plates apart. The advance of theslide then interposes the wedge 31 to positively spread the plates apartand form a plug for the lock. By this time the key has been removed andmay be kept in the pocket, a drawer or any other convenient place untilits application to the plugging unit for the removal of the same isagain required.

It is now apparent that the novel plugging device is a simple andcompact accessory capable of application to any mortise type door lockto render the same proof against attempts to open it with a conventionalkey. Also, the device may be made with a wide variety of combinations inrespect to dimensions and fit between the key and the plugging unit, soas to discourage duplication of keys or plugging units by unscrupulouspersons. Finally, the device is constructed on well establishedmechanical principles, has few parts, and may be mastered and used withfacility by the average person.

While I have described the invention along specific lines, various minorchanges or refine ments may be made therein without departing from itsprinciple, and I reserve the right to employ all such changes andrefinements as may come within the scope and spirit of the appendedclaims.

I claim 1' l. A plugging device for mortise-type door locks comprising aunit having a pair of hinged plates folded sufficiently close to permitthe insertion of the unit into the look through either keyhole when theunit is assembled with a control, means effective on said plates whenthe controlis removed to expand them and constitute the unit a plugbarring the insertion of a regular key into the lock, said meanscomprising a slide with a cam formation effective to gather said plateswhen the slide moves in the direction of said control, and a connectionbetween the latter and the slide to procure said movement thereof.

2. A plugging device for mortise-type door locks comprising a unithaving a pair of hinged plates folded sufficiently close to permit theinsertion of the unit into the lock through either keyhole when the unitis assembled with a control, means effective on said plates when thecontrol is removed to expand them and constitute the unit a plug barringthe insertion of a regular key into the lock, said unit including ahousing, said means comprising a slide with a cam formation effective togather said plates when the slide moves in the direction of saidcontrol, the latter finding a bearing in the housing, other meanschecking the slide from rotary movement relative to the housing, and athreading connection between the control and the slide eirective to movethe same as stated when the control is rotated accordingly.

3. A plugging device for mortise-type door locks comprising a unithaving a pair of hinged plates folded sufficiently close to permit theinsertion of the unit into the look through either keyhole when the unitis assembled with a control, means effective on said plates when thecontrol is removed to expand them and constitute the unit a plug barringthe insertion of a regular key into the lock, said unit including ahousing, said means comprising a slide with a cam formation effective togather said plates when the slide moves in the direction of saidcontrol, the latter finding a bearing in the housing, the slide having atapped bore opposite the control, and a screw extended from the latterand adapted to thread into said bore when the control is rotated in agiven direction to procure the said movement on the part of the slide.

4. A plugging device for mortise-type door locks comprising a unithaving a pair of hinged plates folded sufficiently close to permit theinsertion of the unit into the lock through either keyhole when the unitis assembled with a control, means effective on said plates when thecontrol is removed to expand them and constitute the unit a plug barringthe insertion of a regular key into the lock, said means comprising aslide with a cam formation eifective to gather said plates when theslide moves in the direction of said control, a connection between thelatter and the slide to procure said movement thereof, and yieldablemeans urging the slide in a direction opposite from said control.

5. A plugging device for mortise-type door locks comprising a unithaving a pair of hinged plates folded sufficiently close to permit theinsertion of the unit into the lock through either keyhole when the unitis assembled with a control, means effective on said plates when thecontrol is re-, moved to expand them and constitute the unit a plugbarring the insertion of a regular key into the lock, said meanscomprising a slide with a cam formation effective to gather said plateswhen the slide moves in the direction of said control, a connectionbetween the latter and the slide to procure said movement thereof, and acompression spring interposed between said plates and the end of theslide remote from said control, such spring being eifective to urge theslide in a direction opposite from said control.

6. A plugging device for mortise-type door locks comprising a unithaving a pair of hinged plates folded sufficiently close to permit theinsertion of the unit into the look through either keyhole when the unitis assembled with a control, means effective on said plates when thecontrol is removed to expand them and constitute the unit a plug barringthe insertion of a regular key into the lock, said means comprising aslide with a cam formation efiective to gather said plates when theslide moves in the direction of said control, a connection between thelatter and the slide to procure said movement thereof, and means carriedby the slide and elfective to separate said plates on the returnmovement of the slide.

7. A plugging device for mortise-type door locks comprising a unithaving a pair of hinged plates folded sufiieiently close to permit theinsertion of the unit into the lock through either keyhole when the unitis assembled with a control, means efiective on said plates when thecontrol is removed to expand them and constitute the unit a plug barringthe insertion of a regular key into the lock, said means comprising aslide with a cam formation effective to gather said plates when theslide moves in the direction of said control, a connection between thelatter and the slide to procure said movement thereof, yieldable meanscarried by the slide to urge the said plates apart on the departure ofsaid cam formation, and positive means also carried by the slide andentering between said plates to spread them apart.

8. A plugging device for mortise-type door locks comprising a unithaving a pair of hinged plates folded sufiiciently close to permit theinsertion of the unit into the lock through either keyhole when the unitis assembled with a control, means eifective on said plates when thecontrol is removed to expand them and constitute the unit a plug barringthe insertion of a regular key into the lock, said means comprising aslide with a cam formation effective to gather said plates when theslide moves in the direction of said control, a connection between thelatter and the slide to procure said movement thereof, a hairpin springwith its arms urging the plates apart on the departure of said camformation, and a wedge also carried by the slide and entering betweensaid plates to spread them apart.

PAUL SEVC IIK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,713,602 Heiden May 21, 19291,819,059 Schmid Aug. 18, 1931 FOREIGN PATENTS Number Country Date436,100 Germany Oct. 25, 1926 556,013 Germany Aug. 2, 1932 577,757Germany June 3, 1933

